Guidance Needed: Using Fusion Taxes for Expense Reports & AP Invoices Instead of Vertex

We have a requirement from one of our customers who is currently using Vertex to calculate taxes on Payables, Receivables, and other module transactions. They are now implementing Expenses in Fusion, and for expense-related transactions (Expense Reports and AP transactions), they would like to leverage Fusion Taxes instead of Vertex.

Specifically, they want to create taxes directly in Fusion and have those taxes available in the Tax Classification Code field within the Expense Types setup. however, the taxes are not getting calculated on Expense Report AP Invoices

Has anyone worked on a similar requirement or have experience in this area? Any guidance, best practices or inputs on how this can be achieved using Fusion Taxes would be greatly appreciated.